Bidirectional DC/DC converter based on isolated full-bridge ANPC and H bridge

Abstract

The invention discloses a bidirectional DC / DC converter based on an isolated full-bridge ANPC and an H bridge. The converter comprises a full-bridge ANPC and an inductor which are connected with one side of a transformer, wherein an H bridge circuit is connected with the other side of the transformer, the full-bridge ANPC can output five levels at most, the H-bridge circuit can output three levelsat most, a full-bridge ANPC active bridge is composed of two voltage-dividing capacitors and two half-bridge ANPC three-level circuits, the two voltage-dividing capacitors are connected in series with a bus voltage Vdc, a voltage of each voltage-dividing capacitor is Vdc / 2, the half-bridge ANPC connects a midpoint of a bridge arm of a series switch tube to a series midpoint of the two voltage-dividing capacitors, so the voltage stress borne by the switch tube of each half-bridge ANPC is Vdc / 2; each half-bridge ANPC active bridge can output three levels of Vdc / 2, 0 and-Vdc / 2, the output levelof the full-bridge ANPC is determined by a difference value of the output levels of the two half-bridge ANPCs, and five levels of Vdc, Vdc / 2, 0,-Vdc / 2 and-Vdc can be outputted. The converter can be adapted to application occasions with high voltage conversion ratios.

Description

technical field [0001] The present invention relates to the technical field of DC / DC converters, more specifically, to a bidirectional DC / DC converter based on an isolated full-bridge Active Neutral Point Clamped (ANPC) and H-bridge. Background technique [0002] A DC / DC converter with galvanic isolation and bidirectional power transmission capability can realize power transmission and voltage transformation between grids of different voltage levels. Dual Active Bridge (DAB) DC / DC converter has the advantages of electrical isolation, high power density, bidirectional flow of energy, and easy realization of soft switching, and has been widely used in the fields of renewable energy and DC transmission and distribution. extensive research and applications. [0003] A common DAB topology is a dual H-bridge DAB, where the voltage stress on the switching devices is the DC bus voltage. In many applications, such as the voltage transmission between different voltage levels of the ...

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Problems solved by technology

[0009] Aiming at the defects of the prior art, the purpose of the present invention is to solve the technical problem that the two-way power flow and the on-state loss of the low-voltage side cannot be satisfied at the same time in the case of a large voltage conversion ratio in the prior art

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